﻿#include <iostream>
using namespace std;

int main() {
	int n;
	
	do {
		cout << "正数值：";
		cin >> n;
	} while (n < 0);

	while (n > 0) {
		cout << n % 10;
		n = n / 10;
	}

	cout << '\n';

	cin.get();
	cin.get();
}